Dependent request filter for Web tests

A pretty common need when you are testing your web application is to filter out certain types of dependent requests. For example, if a page you are testing has an ad in it from an external site, you may not want to hit that site in your load tests.

Here is a simple WebTestPlugin that will allow you to filter any dependents that start with a particular string, so you can then easily filter all dependents that go to a particular external site.

using Microsoft.VisualStudio.TestTools.WebTesting;

namespace SampleWebTestRules

{

    public class WebTestDependentFilter : WebTestPlugin

    {

        string m_startsWith;

        public string FilterDependentRequestsThatStartWith

        {

            get { return m_startsWith; }

            set { m_startsWith = value; }

        }

        public override void PostRequest(object sender, PostRequestEventArgs e)

        {

            WebTestRequestCollection depsToRemove = new WebTestRequestCollection();

     // Note, you can't modify the collection inside a foreach, hence the second collection

            // requests to remove.

            foreach (WebTestRequest r in e.Request.DependentRequests)

            {

                if (!string.IsNullOrEmpty(FilterDependentRequestsThatStartWith) &&

                    r.Url.StartsWith(FilterDependentRequestsThatStartWith))

                {

                    depsToRemove.Add(r);

                }

            }

            foreach (WebTestRequest r in depsToRemove)

            {

                e.Request.DependentRequests.Remove(r);

            }

        }

    }

}

Ed.